To seal the space between the opposed vertical edges of the active and inactive doors of a double door installation when the doors are closed, it is common to use a T-shaped astragal mounted along the vertical edge of the inactive door. Such astragals provide a stop against which the active door can close and usually include a weather strip that seals against the closed active door to prevent drafts. To secure the inactive door in its closed position, vertically slidable lock blocks are mounted in the top and bottom ends of the astragal. The lock blocks are formed with bolts that project from the ends of the lock blocks. The lock blocks are slidable between an extended position wherein their bolts project into receptacles in the door frame to secure the inactive door and retracted positions wherein the bolts are withdrawn into the astragal for freeing the inactive door. When the lock blocks are in their extended positions, the inactive door is locked and secured in its closed position. The active door can then be closed against the astragal of the inactive door. A common door knob can be provided in the active door and a corresponding strike plate can be mounted in the astragal along the vertical edge of the inactive door if desired for securing and locking the active door in its closed position.
Double door installations are normally sealed along the hinged edge portions of the doors, along the head jamb of the door frame, and along the astragal by appropriate flexible sealing members or weather strips that are attached to the jamb stops and that engage and compress against the doors when they are closed. The bottom edges of the doors typically are sealed against the door sill either by flexible sweeps secured to the bottom edges of the doors or by an upwardly projecting flexible threshold cap member that engages the bottoms of the doors when they are closed.
Since the jamb stops along the tops of the doors project slightly over the edges of the door faces to provide abutting surfaces for the doors, it is necessary to notch or recess slightly the top end of the astragal so that it does not interfere with the opening and closing of the doors by impacting the jamb stops. It is also necessary to provide a space between the bottom end of the astragal and the threshold cap of the sill for the same reason. The result is an air gap between the top end of the astragal and the head jamb and between the bottom end of the astragal and the door sill that can permit drafts and rain to enter the dwelling. Even though the bolts of the lock blocks extend through these gaps when the inactive door is secured, they do not completely fill the gaps and provide almost no seal against drafts and rain water.
Attempts to seal the gap between the astragal ends and the door frame and sill have been made in the past. U. S. Pat. No. 4,625,457 of Avery, for example, teaches the use of a rubber pad that is attached to the astragal end portions and that has laterally projecting flexible fingers that engage the bottom edge of the active door and the extended bolt of the inactive door when the doors are closed. While this provides some resistance to drafts and water entry on the sides of the gap, it does not seal the bottom of the gap because the pad is fixed to the astragal and a small space must still be provided between the strip and the door jamb and sill to allow opening and closing of the doors. This is a particular problem on the bottom of the astragal because threshold caps of door sills typically are not flat and the pad must be able to clear the highest point of the threshold cap. Thus, the Avery device falls short of providing a reliable seal.
U.S. Pat. No. 4,052,819 of Beischel, et al. teaches lock block having a projecting bolt and being provided on its opposed sides with bristled pads that bear against the edges of the doors. When the lock block is extended to secure the inactive door, the pads move with the block to bear against the door edges at their extreme lower extents and thus to seal the sides of the gap between the bottom of the astragal and the door sill. When in this position, the bottom of the lock block rests against the top of the threshold cap portion of the door sill. As with Avery the Beischel et al. device provides some seal on the sides of the gap but does not provide a seal at the bottom of the gap because the hard bottom surface of the lock block is the only thing that engages the sill. Further, since door frames and sills vary in size and the lock block's extent of travel is fixed, the bottom of the lock block rarely precisely contacts the sill when the lock block is extended and this results in a gap. In addition, for threshold caps that are not flat, the Beischel et al. device provides little if any resistance to drafts and rain water at the bottom of the gap.
U.S. Pat. No. 4,429,493 of St. Aubin teaches the application of a bristled pad to the top of the sill itself. The idea here is that the pad will contact the bottom of the astragal when the door is closed to seal the gap. However, this device fails to address the sealing of the gap on its sides and thus is an inadequate solution. Another device for sealing the gaps between the ends of an astragal and the door frame is disclosed in U.S. Pat. No. 4,644,696 of Bursk. The Bursk device also fails to provide a reliable seal against drafts and water.
Accordingly, there exists a need for a device that provides a reliable and complete seal of the entire gap between the ends of an astragal and a door frame and seal to prevent drafts from entering through the gaps and to prevent rain water from seeping into a dwelling through the gaps. It is to the provision of such a device that the present invention is primarily directed.